LotR -- Book 5 - Chapter 08 - The Houses of Healing

[Formendacil]

I think the use of the terms "leech" and "leechcraft" have more to do with Tolkien evoking the ancientry of Gondor than using bloodsucking worms medicinally.

And! A little bit of quick googling "etymology of leech" leads me to believe we have a classic case of Tolkien attempting to reintroduce aan old meaning to a modern form: "leech" with the archaic meaning of "doctor" apparently has quite a few cognates in Germanic tongues.

That said, the descent of elven derived healing into bloodsucking worms does sound like a bit of a metaphor for the fall of Numenor.

[Inziladun]

Originally Posted by Formendacil

I think the use of the terms "leech" and "leechcraft" have more to do with Tolkien evoking the ancientry of Gondor than using bloodsucking worms medicinally.

It seems you're correct.
As Théoden angrily remarked to Wormtongue in The King of the Golden Hall:

'Your leechcraft ere long would have had me walking on all fours like a beast.'

Théoden, being of part Gondorian descent, could be expected to use some of their expressions.

[William Cloud Hicklin]

Etymology:

leech (n.2)

"physician" (obsolete, poetical, or archaic), from Old English læce "leech," probably from Old Danish læke, from Proto-Germanic *lekjaz "enchanter, one who speaks magic words; healer, physician" (source also of Old Frisian letza, Old Saxon laki, Old Norse læknir, Old High German lahhi, Gothic lekeis "physician"), literally "one who counsels," perhaps connected with a root found in Celtic (compare Irish liaig "charmer, exorcist, physician") and Slavic (compare Serbo-Croatian lijekar, Polish lekarz), from PIE *lep-agi "conjurer," from root *leg- (1) "to collect, gather," with derivatives meaning "to speak (to 'pick out words')."

For sense development, compare Old Church Slavonic baliji "doctor," originally "conjurer," related to Serbo-Croatian bajati "enchant, conjure;" Old Church Slavonic vrači, Russian vrač "doctor," related to Serbo-Croatian vrač "sorcerer, fortune-teller." The form merged with leech (n.1) in Middle English, apparently by folk etymology. In early Middle English also of God and Christ; by 17c. the sense had so deteriorated leech typically was applied only to veterinary practitioners, and soon it was entirely archaic.

The fourth finger of the hand, in Old English, was læcfinger, translating Latin digitus medicus, Greek daktylus iatrikos, supposedly because a vein from that finger stretches straight to the heart.

leech (v.)

"to cure, heal," c. 1200, from Old English also had a verb læcnian, from the source of leech (n.2). Meaning "to apply leeches medicinally" is from 1802 (implied in leeching), from leech (n.1). Related: Leeched.

[Galadriel55]

Well, I just discovered something. I have been assuming that leech=doctor etymologically derived from their use of leeches=bloodsuckers. But having read your comments and done a little search I realized it might well be the other way around, in which case I retract my case. It still sounds jarring with the modern association but it makes perfect sense etymologically.